scholarly journals Natal foraging philopatry in eastern Pacific hawksbill turtles

2017 ◽  
Vol 4 (8) ◽  
pp. 170153 ◽  
Author(s):  
Alexander R. Gaos ◽  
Rebecca L. Lewison ◽  
Michael P. Jensen ◽  
Michael J. Liles ◽  
Ana Henriquez ◽  
...  
Keyword(s):  
Genetic Research ◽  
Eastern Pacific ◽  
Marine Turtle ◽  
Natal Philopatry ◽  
Eretmochelys Imbricata ◽  
Turtle Species ◽  
Marine Turtles ◽  
Complex Processes ◽  
Natal Homing ◽  
Hawksbill Turtles

The complex processes involved with animal migration have long been a subject of biological interest, and broad-scale movement patterns of many marine turtle populations still remain unresolved. While it is widely accepted that once marine turtles reach sexual maturity they home to natal areas for nesting or reproduction, the role of philopatry to natal areas during other life stages has received less scrutiny, despite widespread evidence across the taxa. Here we report on genetic research that indicates that juvenile hawksbill turtles ( Eretmochelys imbricata ) in the eastern Pacific Ocean use foraging grounds in the region of their natal beaches, a pattern we term natal foraging philopatry. Our findings confirm that traditional views of natal homing solely for reproduction are incomplete and that many marine turtle species exhibit philopatry to natal areas to forage. Our results have important implications for life-history research and conservation of marine turtles and may extend to other wide-ranging marine vertebrates that demonstrate natal philopatry.

Long-distance migrations by the hawksbill turtle, Eretmochelys imbricata, from north-eastern Australia

1998 ◽  
Vol 25 (1) ◽  
pp. 89 ◽  
Author(s):  
Jeffrey D. Miller ◽  
Kirstin A. Dobbs ◽  
Colin J. Limpus ◽  
Neil Mattocks ◽  
André M. Landry Jr
Keyword(s):  
Adult Female ◽  
Solomon Islands ◽  
Satellite Telemetry ◽  
Marine Turtle ◽  
Long Distance ◽  
Eretmochelys Imbricata ◽  
Turtle Species ◽  
Eastern Australia ◽  
Nesting Beaches ◽  
Hawksbill Turtles

Tag recoveries from four adult female hawksbill turtles, Eretmochelys imbricata, tagged on the Great Barrier Reef, Australia, are reported. Hawksbill turtles on breeding migrations move between Australia and neighbouring countries including Vanuatu, Solomon Islands, Papua New Guinea and Indonesia. Migratory distances between foraging areas and nesting beaches ranged from 368 to 2425 km. A review of data from tag recoveries, genetic analysis and satellite telemetry indicates that adult female hawksbill turtles often exhibit migratory behaviour parallelling that of other marine turtle species. This study refutes the myth that hawksbill turtles remain resident at reefs associated with their nesting beaches.

scholarly journals Signs of hope in the eastern Pacific: international collaboration reveals encouraging status for a severely depleted population of hawksbill turtles Eretmochelys imbricata

Oryx ◽  
2010 ◽  
Vol 44 (4) ◽  
pp. 595-601 ◽  
Author(s):  
Alexander R. Gaos ◽  
F.A. Abreu-Grobois ◽  
J. Alfaro-Shigueto ◽  
D. Amorocho ◽  
R. Arauz ◽  
...  
Keyword(s):  
El Salvador ◽  
Working Group ◽  
Eastern Pacific ◽  
Marine Turtle ◽  
Current Status ◽  
Eretmochelys Imbricata ◽  
Conservation Projects ◽  
Available Information ◽  
Nesting Activity ◽  
Hawksbill Turtles

AbstractWhile little is known about hawksbill turtles Eretmochelys imbricata in the eastern Pacific Ocean, available information suggests that the population has declined substantially in recent decades and could be near extirpation in the region. To evaluate the current status of the population more effectively and to determine the feasibility of recovery efforts, a workshop of regional marine turtle specialists was held in June 2008 in Los Cóbanos, El Salvador. An international working group, Iniciativa Carey del Pacífico Oriental (ICAPO; Eastern Pacific Hawksbill Initiative in English), was established to consolidate information, promote conservation projects and raise awareness about the species. We present information derived from the workshop and compiled by the ICAPO working group since that time. Considering only records from 1 January 2007 to 31 May 2009 it appears that El Salvador hosts the majority of known hawksbill turtle nesting activity in the eastern Pacific, with 79.6% (n = 430) of all nesting observation records, and Mexico hosts the majority of records of hawksbill turtles at sea, with 60.3% (n = 44) of all in-water observation records. Although current abundance is very low, the pervasiveness of the species in the region suggests potential for conservation and recovery. Despite a historical paucity of research focusing on this population, the relatively large and steadily increasing number of records as a result of concerted efforts demonstrates the viability of the ICAPO network as an instrument to promote conservation of this species in the eastern Pacific.

scholarly journals First record of the marine turtle leech (Ozobranchus margoi) on hawksbill turtles (Eretmochelys imbricata) in the inner granitic Seychelles

2018 ◽  
Vol 85 (1) ◽  
Author(s):  
Byron M. Göpper ◽  
Nina M. Voogt ◽  
Andre Ganswindt
Keyword(s):  
Chelonia Mydas ◽  
First Record ◽  
The Other ◽  
Marine Turtle ◽  
Eretmochelys Imbricata ◽  
History Museum ◽  
Turtle Species ◽  
Routine Monitoring ◽  
Hawksbill Turtles ◽  
Cousine Island

Ozobranchus spp. are leeches that feed solely on turtle blood. They are common ectoparasites found on a range of marine turtle species, with some species of the leech being implicated as vectors of fibropapilloma-associated turtle herpesvirus (FPTHV). Green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) turtles are the two commonly occurring species in the inner granitic islands of the Seychelles. Routine monitoring of nesting turtles on Cousine Island, Seychelles, allowed for opportunistic sightings of leeches on two hawksbill females. In both cases infestation was low, with three leeches collected off one female turtle and five off the other. No obvious signs of papillomas secondary to infection of FPTHV were seen. All of the turtle leeches collected were determined to be Ozobranchus margoi as they had five pairs of lateral digiform branchiae. The specimens were deposited in the Seychelles Natural History Museum on Mahé. To the best of our knowledge this is the first record of Ozobranchus margoi recorded in the inner granitic Seychelles on hawksbill turtles.

scholarly journals Plastic ingestion by freshwater turtles: a review and call to action

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam G. Clause ◽  
Aaron J. Celestian ◽  
Gregory B. Pauly
Keyword(s):  
Marine Species ◽  
Marine Turtle ◽  
Freshwater Turtle ◽  
Freshwater Turtles ◽  
Plastic Pollution ◽  
Potential Threat ◽  
Implementation Quality ◽  
Turtle Species ◽  
Marine Turtles ◽  
Conservation Concern

AbstractPlastic pollution, and especially plastic ingestion by animals, is a serious global issue. This problem is well documented in marine systems, but it is relatively understudied in freshwater systems. For turtles, it is unknown how plastic ingestion compares between marine and non-marine species. We review the relevant turtle dietary literature, and find that plastic ingestion is reported for all 7 marine turtle species, but only 5 of 352 non-marine turtle species. In the last 10 years, despite marine turtles representing just 2% of all turtle species, almost 50% of relevant turtle dietary studies involved only marine turtles. These results suggest that the potential threat of plastic ingestion is poorly studied in non-marine turtles. We also examine plastic ingestion frequency in a freshwater turtle population, finding that 7.7% of 65 turtles had ingested plastic. However, plastic-resembling organic material would have inflated our frequency results up to 40% higher were it not for verification using Raman spectroscopy. Additionally, we showcase how non-native turtles can be used as a proxy for understanding the potential for plastic ingestion by co-occurring native turtles of conservation concern. We conclude with recommendations for how scientists studying non-marine turtles can improve the implementation, quality, and discoverability of plastic ingestion research.

scholarly journals Two hundred years after a commercial marine turtle fishery: the current status of marine turtles nesting in the Cayman Islands

Oryx ◽  
2001 ◽  
Vol 35 (2) ◽  
pp. 145-151 ◽  
Author(s):  
Jonathan J. Aiken ◽  
Brendan J. Godley ◽  
Annette C. Broderick ◽  
Timothy Austin ◽  
Gina Ebanks-Petrie ◽  
...  
Keyword(s):  
Chelonia Mydas ◽  
Marine Turtle ◽  
Current Status ◽  
Cayman Islands ◽  
Eretmochelys Imbricata ◽  
Marine Turtles ◽  
Mature Adults ◽  
Large Populations ◽  
Sexually Mature ◽  
Insight Into

AbstractLarge populations of marine turtles breeding in the Cayman Islands were drastically reduced in the early 1800s. However, marine turtle nesting still occurs in the islands. The present-day status of this nesting population provides insight into the conservation of marine turtles, a long-lived species. In 1998 and 1999, the first systematic survey of marine turtle nesting in the Cayman Islands found 38 nests on 22 beaches scattered through the three islands. Three species were found: the green Chelonia mydas, hawksbill Eretmochelys imbricata and loggerhead Caretta caretta turtles. Comparison with other rookeries suggests that the small number of sexually mature adults surviving Cayman's huge perturbations may be impeding population recovery. This shows the need to implement conservation measures prior to massive reductions in population size.

Intake and excretion of arsenicals in green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata)

2011 ◽  
Vol 8 (1) ◽  
pp. 19 ◽  
Author(s):  
Tetsuro Agusa ◽  
Kozue Takagi ◽  
Todd W. Miller ◽  
Reiji Kubota ◽  
Yasumi Anan ◽  
...  
Keyword(s):  
Feeding Behaviour ◽  
Chelonia Mydas ◽  
Water Soluble ◽  
Marine Animals ◽  
Eretmochelys Imbricata ◽  
Accumulation Pattern ◽  
Turtle Species ◽  
Green Turtles ◽  
Hawksbill Turtles ◽  
Prey Items

Environmental context Although among higher marine animals, relatively high concentration of arsenic and unique distribution of arsenic compounds are found in green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata), the accumulation mechanism remains unknown. We examined the accumulation of arsenicals in two turtles from the standpoint of short- and long-term intake and excretion and found that prey items might be important for the arsenic accumulation. This study can provide useful information on the accumulation pattern of arsenic speciation in sea turtles. Abstract We analysed arsenic (As) compounds in the stomach and intestine contents, bile and urine of green (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) to understand As accumulation through intake and excretion. Stable isotopes of δ15N and δ13C were also measured for understanding the feeding behaviour dependent accumulation of As. Major As species in gastrointestinal contents were unknown water-soluble As, followed by unextracted As. Concentrations of AB and DMA in the tissues were higher than those in the stomach contents (prey items), indicating high bioaccumulation of these arsenicals. In green turtles, AB concentration was high in bile and increased throughout the gastrointestinal tract, suggesting significant biliary excretion of AB. δ15N was positively correlated with AB level in green turtles, whereas a negative relationship between residual As and δ15N was observed in hawksbill turtles. This study indicates feeding behaviour-dependent accumulation of As compounds in both turtle species for the first time.

International Movements of Adult Female Hawksbill Turtles (Eretmochelys imbricata): First Results from the Caribbean's Marine Turtle Tagging Centre

2011 ◽  
Vol 10 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Julia A. Horrocks ◽  
Barry H. Krueger ◽  
Marina Fastigi ◽  
Emile L. Pemberton ◽  
Karen L. Eckert
Keyword(s):  
Adult Female ◽  
Marine Turtle ◽  
Eretmochelys Imbricata ◽  
First Results ◽  
Hawksbill Turtles

scholarly journals Assessing coastal artificial light and potential exposure of wildlife at a national scale: the case of marine turtles in Brazil

2020 ◽  
Vol 29 (4) ◽  
pp. 1135-1152 ◽  
Author(s):  
Liliana P. Colman ◽  
Paulo H. Lara ◽  
Jonathan Bennie ◽  
Annette C. Broderick ◽  
Juliana R. de Freitas ◽  
...  
Keyword(s):  
Nest Site Selection ◽  
Marine Turtle ◽  
Conservation Strategies ◽  
Brazilian Coast ◽  
Light Pollution ◽  
Artificial Light ◽  
Turtle Species ◽  
Marine Turtles ◽  
Light Levels ◽  
Nesting Beaches

AbstractCoastal areas provide critical nesting habitat for marine turtles. Understanding how artificial light might impact populations is key to guide management strategies. Here we assess the extent to which nesting populations of four marine turtle species—leatherback (Dermochelys coriacea), olive ridley (Lepidochelys olivacea), hawksbill (Eretmochelys imbricata) and two subpopulations of loggerhead (Caretta caretta) turtles—are exposed to light pollution across 604 km of the Brazilian coast. We used yearly night-time satellite images from two 5-year periods (1992–1996 and 2008–2012) from the US Air Force Defense Meteorological Satellite Programme (DMSP) to determine the proportion of nesting areas that are exposed to detectable levels of artificial light and identify how this has changed over time. Over the monitored time-frame, 63.7% of the nesting beaches experienced an increase in night light levels. Based on nest densities, we identified 54 reproductive hotspots: 62.9% were located in areas potentially exposed to light pollution. Light levels appeared to have a significant effect on nest densities of hawksbills and the northern loggerhead turtle stock, however high nest densities were also seen in lit areas. The status of all species/subpopulations has improved across the time period despite increased light levels. These findings suggest that (1) nest site selection is likely primarily determined by variables other than light and (2) conservation strategies in Brazil appear to have been successful in contributing to reducing impacts on nesting beaches. There is, however, the possibility that light also affects hatchlings in coastal waters, and impacts on population recruitment may take longer to fully manifest in nesting numbers. Recommendations are made to further this work to provide deeper insights into the impacts of anthropogenic light on marine turtles.

scholarly journals Shifting the life-history paradigm: discovery of novel habitat use by hawksbill turtles

2011 ◽  
Vol 8 (1) ◽  
pp. 54-56 ◽  
Author(s):  
Alexander R. Gaos ◽  
Rebecca L. Lewison ◽  
Ingrid L. Yañez ◽  
Bryan P. Wallace ◽  
Michael J. Liles ◽  
...  
Keyword(s):  
Life History ◽  
Habitat Use ◽  
Eastern Pacific ◽  
Life History Strategies ◽  
Evolutionary Trajectory ◽  
Eretmochelys Imbricata ◽  
Management Perspective ◽  
Novel Habitat ◽  
Marine Wildlife ◽  
Hawksbill Turtles

Adult hawksbill turtles ( Eretmochelys imbricata ) are typically described as open-coast, coral reef and hard substrate dwellers. Here, we report new satellite tracking data on female hawksbills from several countries in the eastern Pacific that revealed previously undocumented behaviour for adults of the species. In contrast to patterns of habitat use exhibited by their Caribbean and Indo-Pacific counterparts, eastern Pacific hawksbills generally occupied inshore estuaries, wherein they had strong associations with mangrove saltwater forests. The use of inshore habitats and affinities with mangrove saltwater forests presents a previously unknown life-history paradigm for adult hawksbill turtles and suggests a potentially unique evolutionary trajectory for the species. Our findings highlight the variability in life-history strategies that marine turtles and other wide-ranging marine wildlife may exhibit among ocean regions, and the importance of understanding such disparities from an ecological and management perspective.

scholarly journals The evolution of the flippers and the paleoecology of Panchelonioidea (Testudines, Cryptodira)

2015 ◽  
Author(s):  
Isadora Gerheim ◽  
Pedro S. R. Romano
Keyword(s):  
Sister Group ◽  
Marine Turtle ◽  
Benthic Habitat ◽  
Remarkable Feature ◽  
Fossil Species ◽  
Turtle Species ◽  
Marine Turtles ◽  
The Family ◽  
Family Level ◽  
Pelagic Habitat

Background. The recent data on Panchelonioidea’s phylogeny suggested the family level relationships as (Toxochelyidae, (Cheloniidae, (Protostegidae, Dermochelyidae))). Despite the similarity between their limbs, it is known that the flippers morphology on marine turtles evolved independently in these clades. A remarkable feature is the presence of phalangeal condyles in Toxochelyidae and basal Protostegidae, a plesiomorphic state that allows the movement of the hand. On the other hand, the apomorphic state of having a rigid paddle is found in modern turtles (Cheloniidae and Dermochelyidae). Also, living Chelonioidea (Cheloniidae and Dermochelyidae) has the longest length of the hand and the shortest length of the humerus compared to other Testudines, as analyzed by Joyce and Gauthier (2004, Proc. R. Soc. Lond. B, 271). Methods. We took measurements of the forelimb (the length of humerus, ulna and digit III) from five Panchelonioidea fossil species (Protostega gigas, Toxochelys latiremys, Allopleuron hoffmanni, Eochelone brabantica and Archelon ischyros) using ImageJ 1.48v. The percentages of the length of the hand and the humerus with respect to the whole limb were then calculated. The percentages of the five species were added to the two-dimension ternary diagram made by Joyce and Gauthier (2004) in order to evaluate the plot of these species and compare them to other turtles. Results. Archelon ischyros was plotted near Toxochelys latiremys. The Toxochelidae are the sister group of Chelonioidea and they are known to have a poor development of the limbs into flippers and a preference for shallow and benthic habitat. Both were located near non-marine turtle species, showing that they had the relatively shortest hand within Panchelonioidea, whereas Protostega gigas, Allopleuron hoffmanni and Eochelone brabantica was plotted close to the recent Cheloniidae. Discussion. The results suggest a less pelagic habitat for Protostega gigas and Archelon ischyros, resembling a hypothesis formulated by Hay (1905, Bull. Am. Mus. Nat. Hist., 21) that Archelon was not as pelagic as Dermochelys and by Wieland (1909, Am. Jour. Sci., 27) that this species did not have a powerful type of muscular insertion, maybe indicating a less strong swimming power. These results together with the fact that basal species of Protostegidae retain the phalangeal condyles, suggests that after the split between these families, the flippers retained the primitive length of limbs. It also brings back a Zangerl’s hypothesis (1980, Amer. Zool., 20) of a Chelydra-like ancestor for Panchelonioidea, with unspecialized limbs. As conclusion, we suggest that Panchelonioidea ancestor flipper condition would last in stem Toxochelyidae and stem Chelonioidea and then get independently specialized in Cheloniidae and Dermochelyidae.

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